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measurements – use gas analyzer, the adjustment should be performed by
trained technician.
The adjustment of the combustion process is performed by regulation of the
air flow rate as well as the its distribution. The air, consumed at the combustion
process is drawn in to the fuel hopper chamber as well as the burner’s nozzle, by
the flue gases fan. This air is distributed by an air box , where it is preheated and
directed to the fuel hopper chamber (this air is named “primary air”) and to the
burner’s nozzle (this air is named “secondary air”). The air distribution is
adjusted by position of a primary air control flap (which is positioned above the
orifice for air inflow). The primary air, which is drawn in the fuel hopper
chamber is utilized for sustaining the wood gasification (so called pyrolisis)
process. The secondary air is utilized for oxidation of the volatile gases, which
are passing the burner’s nozzle. These gases are mixed with the preheated
secondary air, mixed and oxidized in the combustion chamber of the boiler. The
above described process allows fuel efficient utilization and low running costs
of the heating system. The process could be treated as gas-combustion, because
most of the fuel is gasified and combusted in the oxidation chamber of the
boiler. The design of the boiler allows optimal conditions for the combustion
process and high thermal efficiency, as well as easy control of the thermal
capacity and boiler’s operating mode. The adjustment of the position of the
primary air flow rate control flap requires knowledge of the boiler’s operation,
combustion process and fuel properties, as well as patience, shown by the
technician, in order to achieve optimal results. The practice shows that any
variation of the primary air control flap position, influences the operating
conditions of the boiler with a delay of approximately 15 to 30 minutes, so in
case of position changing, one should wait al least 15 minutes (better wait 30
minutes) in order to get new steady-state operating mode of the boiler and the
influence of the flap position to get sensible effect on the combustion process.
The distribution of the air is performed with appropriate adjustment of the
primary air control flap, as well as adjustment of the air control flap, driven by
the chain, hanged on the lever of the thermovalve (mentioned above). The
following figures show details about the air control adjustment. NOTE : there is
a manual observation orifice and one could verify the position of the primary air
control flap.
